Means for controlling fluid-compressors.



PATENTED DEC. 25, 1906.

Si HVLIBBY. MEANS FOR CONTROLLING FLUID OOMPRESSORS.

"T TQ\\ WVUWO R SAM. h. u ESBY.

2 SHEETS-SHEET APPLICATION FILED JUNE 6,1904.

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PATEIITED D A"). 25, N06.

2 smms-smm 2.

LIBBY. m FOR OOLYJTROLMNG- PLUIM MBA . Improvements in Means for Controlling among the several compressors.

'is'that of aniair-bra which a plurality of air-compressors at difier- UNITED "STATES PTENT OFFICE.

SAM H. LIBBY, OF EAST ORANGE, NEW JERSEY, ASSIGNOR To GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

MEANS FQROONTROLLING FLUID-COM PRESSORS- I Specification of Letters Patent.

Patented Dec. 25, 1906.

Applicaticnfiled June 6. 1904- Serinl No. 211.261-

To all 'whom it may concern:

Be it known that I, SAM H. LIBBY JL citizen of the United States, residing at East Oran e, county of Essex, State of New Jerfiave invented certain new and useful Fluid-Compressors, as ecificat1on..

y invention relates to the control of pumps or fluid-compressors, and refers parof which the following is ticularly to the control of a plurality of Humps or compressors supplying compressed 'uid to a common receptac e. p v -The object of myinvention is to provide a control system for automatically maintain-- proper ressure and at the same time for dividing the. work in proper proportions A case to which in .invention ispapplicable lie system on a train in cut points on the train supply air to areservoir-line running the entire length of the train and in which constant pressure must be maintained. It is common ractice to provide each air-compressor wit-ll an aut0 matic governor which will. start the motor driving the compressor whenever the pressure falls below the desired limit and which will stop the motor when the pressure is again raised to the pro er amount. In order to distribute the wor properly among the several compressors, it is necessary to adjust the several overnors with care, so that they will responc? simultaneously to variations in pressure.

The object of my invention is to rovide a novel form of governor and a nove arrange-' V mt of the control system which shall render unnecessary a careful adjustment of the governors. The overnor' is connected both to. the reservoirinc and to the reservoir charged from the compressor controlled by compressor at work, raising the pressure in v the line, this pressure can have no effect upon the 'other reservoirs, and the difference in pressure created between the train-line and 'the other reservoirs produces an immediate response of the other governors, which set their respective compressors at work to charge their reservoirs. In this way the work is properly distributed among the several'compressors. v

My invention will best be understood by reference to the accompanying drawings, in which Figure 1 shows diagrammatically an arrangement embodyingmy invention as ap plied to the control of a plurality of compressors jointly suppl ing a reservoir-line.

ig. 2 shows a front e evation of the difierential governor. Fig. 3 shows a side elevation of the same partly in cross-section, and Fig. 4 shows a plan view of the contacts carried at the ti of the governor-levers.

. In Fig. 1' Fhave shown the equipment for two cars of the train. L represents the reservoir-line extending the length of the train and supplied from the reservoirs R R, which are charged from the compressors O .C, driven by the motors M M. S represents a solenoid or magnet-coil controlling the switch 8 in the circuit of motor M. The core of solenoid S also carries the bridging member s. I represents a resistance, and b a blow-out coil for the switch 8. D represents the differential governor, which comprises two diaphragmsd and d, which are connected to the reservoir R and the reservoirline L by the pipes r and Z, respectively, V represents a check-valve inserted between the reservoir R and reservoir-line L, permittin a free flow of air from reservoir to line an preventing the flow in the opposite direction. The check-valve V is shown in crosssection. T represents the trolley, collectorshoe, or other source of current for the circuit of motor M.

Neglecting for a moment the construe-Lion and arrangement of the differential governor D, the general operation of the system will be briefly described.

With normal pressure in reservoir-line L and in reservoirs R and R solenoids S and S are both denergized, and the circuits of both motors M and M are open. Now assume that the air is exhausted from the reservoirline, so as to lower the pressure below the minimum limit. The pressure in hotli reservoirs B. and it will also be lowered. Now assume that the diiierential governor D responds to the lowering of pressure before differential governor D. Solenoid S will then. be energized by a circuit from trolley T to upper terminal of solenoid :3 through the entire winding and from the lower terminal through conductor 3 and the contacts of differential governor D to earth E. Solenoid S will consequently raise its core, closing switch 8, thereby starting the motor and at the same time raising the bridging member s and closing a maintainingcircuit for itself from trolley T, upper terminal of solenoid S, middle terminal, resistance 1, bridging member s to earth. Motor M will. consequently start, driving controller C and raising the ressure in reservoir R and in reservoir-line L. Check-valve V will prevent the How of air from reservoir-line to reservoir It, so that the pressure in reservoir R will not be raised. A difference of pressure will then exist on the twodiaphragms d and d of difi'erential governor D. As has already been stated, and as will hereinafter be explained, the differential governor is responsive to a dinerence in pressure, as well as to a simultaneous variation of pressure, on the diaphragms. Consequently differential governor D will close the circuit of solenoid S, which will s the motor M and close its own maining-circuit in a manner heretofore descr ed. This will continue until the maximu. limit of pressure is reached in the two reser airs and in the reservoir-line. When this limit is reached, the diiierential governors act to-connect the lower terminals of solenoids S and. S to the trolley T and T. Current is then passing in opposite directions in the two halves of the solenoids. The cores are consequently deenergized, and the motor-circuits are opened, stopping the operation oi the compressors.

Referring now to Figs. 2 and 3, d and. d represent the two diaphragms, which are connected by the pipes r and Z to reservoir and to reservoir-line, respectively. The diaphragms are shown in Fig. 3 in low-pressure position. When the pressure rises in pipes '2 and Z, the two diaphragms are pushed forward to engage pistons e and a, respectively, which carry spindles bearing against the pivoted arm F and the pivoted link 9, respectively, which are held pressed against the spindles by the springs J and J. Arm F is pivoted atf, and the link 9 is pivoted at g. G is a second arm, which is pivoted at f to arm F and at g to tholink g. The arm F carries at its upper end two contacts i and i, and arm G carries the single contact 7c, as shown in Fig. 4. The contact i is connected by conductor 1 to earth, as indicated. in Fig.

1. Qcntact i is connected. byconductor :3 to the upper nii al of solenoid S, as shown in Fig. l, and contact 7.: is con to by the corn doctor 3 to the lower rzninal oi solenoid 5.

The operation is follows: iv'ith. the dia-- phragms in the low-pressure position shown, arm h and link 7 are both pushed ii ally in the position shown by the spring J and J", respectively. Since the pivots and 9" are both pressed inward an ecpual amount, the ever-arm G is not deflected from its ical position. The arm l ,however, is deflected, as shown in Fig. 3, so as to bring contact i into engagement with Contact is. This connects the lower terminal of solenoid S to ground, so as to energize the solenoid and close the motor-circuit, has been thereto fore explained. if the pressure in pipes and Z rise at an equal rate, pistons e c will be pushed outward at the same rate and pivots and 9 will travei at the same rate also, so that arm G will still maintain its vertical position. The outward movement of piston e, however, produces a movement of arm F, so as to withdraw contact "L from contact 7c. The lower terminal of solenoid S is consequently disconnected. from ground; but the solenoid remains ene git Jed, i it has closed its own maintaining-circuit, as has been heretofore explained. This continues until arm F has been moved such a distance as to bring contact i into engagement with cont-act 713'. A circuit is then closed from the trolley T to the lower terminal of the solenoid, whereupon the solenoid do nergized and opens the motorwircnit, has been heretofore explained.

Thus if pressure rises simultaneously and at an equal rate in reservoir and reservoir-line, the governor acts as a simple governor, opening and closing the motor-circuits when. the upper and lower pressure limits reached, one of the arms remaining practically stati'onary and the other responding to variations in pressure in both reservoir and resorvoirline. If, however, the pressure at any time is not equal in pipes r and Z, a movement of thepivoted arm Gis produced. Tl, for instance, while contact Z". is midway between contacts t and i and the inotor-circuit is open the pressure in the reservoir-line falls a sufficicnt amount to cause one oi the other governors to respond, so as to start its compressor, the pressure in pipe L will be increased, while the pressure in reservoir it will not be changed, owing to the presence of check-valve V of Fig. 'l. Pivoted link will consequently be pushed outward by dia* phragm d, while pivoted arm F will. remain stationary. Pivot f consequr-intly remains stationary, while pivot 9 moves outwardly. A movement of arm G is thereby produced, so to bring contact 7c into engagcmci'it with contact 01. Lhesolenoid is then. cner-- ITO ized,so as to close the -circuit. Arm is slotted at pivot f, as shown in dotted lines, in order to permit of relative movement between pivots f and 9 Thus it will be seen that one of the two arms responds to the simultaneous variation of pressure upon the two diaphragms, and the other arm responds to a relative variation of pressure upon the two diaphragms, and that by means of this differential action an equal division of load among the several compressors may be obtained. By means of the set-screws and j,

(shown in Fig. 3) the pressure of springs J and J may be adjusted, thereby adjusting the action of the governor.

Although I have shown my invention'as applied to an air-brake system on trains, it is evident that it is not limited to this particular application, but may be used to advantage wherever a plurality of pumps or fluidcompressors are employed to supply a given fiuidreceptacle. Furthermore, the construction and arrangement of parts may be greatly modified without departing from the spirit of my invention, and I aim in. the appended claims to cover all such modifications. For instance, the diaphragms may be simple diaphragms, as shown, or any other suitable device responsive to variations in fluid-pressure may be employed, and b the term diaphragm in the appended claims I intend to cover all devices, whether simple diaphragms or not, which respond to variations in fluid-pressure.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In combination, a plurality of fluidcompressors, a common receptacle supplied thereby, checlevalves between the several compressors and said receptacle, and governors controlling the several compressors, each of said governors being responsive both to simultaneous and to relative variations of pressure in the compressor and receptacle.

2. In combination, a plurality of reservoirs, a common receptacle supplied thereby, check valves between the several compressors and said receptacle, compressors for charging the several reservoirs, andgovernorscontrolling the several compressors, each of said governors being responsive both to simultaneous and to relative variations of pressure in the reservoir and receptacle.

3. In an air-brake system, a reservoir-line, a plurality of reservoirs for supplying said line, check-valves between said hue and the several reservoirs, compressors for charging the several reservoirs, and governors controlling the several compressors, each of said governors being responsive both to simultaneous and to relative variations of the pressure in the reservoir and reserv oir-line.

4. In an automatic pressure-governor, two diaphragms subjected to pressures from different sources, levers actuated by the movement of said diaphragms and arranged to respond both to a simultaneous and to a relative movement of said diaphragms, and controlling mechanism controlled lay ,the movement of said levers.

5. In an automatic pressure-governor, two diaphragms subjected to pressures from different sources, levers actuated by the movement of said diaphragms, one of said. levers responding to a simultaneous IIlOV9- ment and another to a relative movement of said diaphragms, and controlling mechanism controlled by the relative movement of said levers.

6. In an automatic governor, two dia phragms subjected to pressures from different sources, levers actuated by the movement of said diaphragms and arranged to respond both to a simultaneous and to a relative movement of said diaphragms, a contact carried by one lever, and two contacts carried by a second lever and arranged to be brought respectivelyinto engagement with the first contact upon a relative movement of said levers in one direction or the other, and an electroresponsive controlling device controlled by said contacts.

7. In an automatic pressure-governor, two diaphragms subjected to pressures from different sources, levers actuated by the movement of said diaphragms, one of said levers responding to a simultaneous movement and another to a relative movement of said diaphragms, a contact carried byone of said levers, two contacts carried by the second lever and arranged to be brought respectively into engagement with the first contact upon a relative movement of said levers in one direction or the other, and an electroresponsive controlling device controlled by said contacts.

8. In an automatic pressure-governor, two diaphragms subjected to pressures from diflcrent sources, a pivoted lever actuated by one diaphragm, a pivoted link actuated by the other diaphragm, a second lever carried jointly by said link and the first lever, and controlling mechanism controlled by said levers.

9. In an automatic pressure-governor, two diaphragms subjected to pressure from different sources, a pivoted lever actuated by one diaphragm, a pivoted link actuatedby the other diaphragm, a second lever carried jointly by said link and the first lever, contacts carried by said levers, and an electroresponsive controlling device controlled by said contacts. j

10. In combination, a plurality ol reservoirs, 'a common receptacle supplied thereby, checlevalves between the several reservoirs and said receptacle, compressors for charging the several reservoirs and governors COD? trolling the several compressors, each of said reservoir and the receptacle, and levers actu ated by the movement of said diaphragms and arranged to respond both to simultaneous and to relative movement of said diaphragms.

12. In combination, a plurality of reservoirs, a common receptacle supplied thereby, check-valves between the several reservoirs and saidreceptacle, compressors for charging the several reservoirs and governors controlling the several compressors, each of said overnors comprising two diaphragms sub- 1ected respectively to the pressures of the reservoir and the receptacle, andlevers actuated by the movement of said diaphragms, one of said levers being responsive to a simultaneous movement and another to a relative ;movement of said diaphragms.

13. In an apparatus of the character described, the combination with an air-pump, a

main reservoir, and a main-reservoir pipe-line connected to saidv reservoir with means for preventing backflow to the reservoir, of a movable'abutment operated by main-reservoir pressure for controlling said pump, and means operated through the pressure of the main-reservoir pipe-line for also controlling said pump.

'14. In an apparatus of the character described, the combination with an air-pump, a main reservoir, and a main-reservoir pip e-line connected to said reservoir with means for preventing backflow to the reservoir, of a movable abutment operated by main-reservoir pressure for controlling said pump, and

means operated through the pressureot the main-reservoir pipe-line for controlling the action of said movable abutment.

15. In an apparatus of the character described, the combination with an air-pump, a

main reservoir, and a main-reservoir pip e-line connected to said reservoir with means for preventing backflow' to the reservoir, of means operated by the opposing pressures of the main reservoir and the main-reservoir pipeline for controlling said pump.

16. In a braking system, a reservoir-line, a reservoir, a pump, and means positioned between said reservoir-line and said pump adapted upon an increase in pressure taking seaeoe place in said reservoir-line to cause the operation of said pump.

17. In a braking system, a reservoir-line, a reservoir, a pump, and means positioned between. said reservoirdine and said pump adapted upon an increase in pressure taking place in said reservoir-line to cause said pump to force air into said reservoir.

18. In a braking system, a reservoir-line, a reservoir, a pump, and means positioned between said. reservoir-line and said pump adapted upon an increase in pressure taking place in said reservoir-line to complete an electric circuit controlling the operation oi said pump.

19. In a braking system, a reservoir-line, a reservoir, a pump, and means adapted upon an increase in pressure taking place in said reservoir-line to cause said pump to force air into said reservoir.

20. In a braking system, a reservoir-line, a plurality of reservoirs, a plurality of pumps, and means positioned between each of said reservoirs and said reservoir-line adapted upon an increase in pressure taking place in said reservoir-line to cause the corresponding pump to force air into the corresponding reservoir.

21. In a braking system, a reservoir-line, a reservoir, a pump, means adapted upon the fall of pressure in said reservoir-lino to a certain predetermined point to cause said pump to force air into said reservoir, and means adapt-ed upon the pressure in said reservoirline exceeding that in said reservoir to cause a similar action of said pump.

22. In a controlling apparatus, two receptacles adapted to contain a iluid under pressure, a connection between the same, and means positioned in said connection adapted upon the pressure in one of said receptacles increasing to complete an electric circuit.

23. In a controlling apparatus, two receptacles adapted to contain a fluid under pres-- sure, a connection between the same, and means positioned in said connection adapted upon the pressure in one of said receptacles becoming greater than that in the other to complete an electric circuit.

24. In a controlling apparatus, two receptacles adapted to contain a fluid under pressure, a connection between the same, and means positioned in said connection adapted upon the pressure in one of said receptacles becoming greater than that in the other to cause the operation of means adapted to increase the pressure in said other receptacle.

In witness whereof I have hereunto set my hand this 1st day of June, 1904.

SAM I-I. LIBBY. Witnesses:

ANNA 1i. GrLLiN, Roenn H. Bnr'rnnwon'rn. 

